1. Royal London Hospital for Integrated Medicine, UCLH NHS Trust, London, UK
2. Deceased, formerly Department of Primary Care, University of Southampton, Southampton, UK
3. Department of Health Sciences, University of York, York, UK
4. Institute for Complementary and Integrative Medicine, University of Zurich and University Hospital Zurich, Zurich, Switzerland
5. Deceased, formerly Royal London Hospital for Integrated Medicine, UCLH NHS Trust, UK